Patent GB-1470715-A (GB)
Title: Lighting system for a motor cycle
IPC: B60Q1/115
Filed: 1974-04-01
Abstract: 1470715 Adjusting vehicle headlamps J M ALPHEN 1 April 1974 [2 April 1973] 14307/74 Heading F4R A system for correcting the orientation of the headlamp of a motor cycle or similar two-wheeled vehicle when the vehicle makes a turn comprises means for pivoting at least the optical system of the headlamp, or alternatively the entire lamp, about an axis generally parallel to the optical axis of the lamp and a transducer which controls the pivoting means and is sensitive to the inclination of the vehicle during the turn. In a first embodiment, Figs. 4 and 6, the sealed beam unit 10 is mounted in a guide ring 13 which can rotate between three rollers 14a- 14c and carries a toothed ring 16. The axis of rotation YY<SP>1</SP> is inclined forwardly and downwardly relatively to the optical axis XX<SP>1</SP> by an angle of up to 15 degrees. The transducer comprises a weight 52 slidable inside a casing 51 under the action of centrifugal force against the resistance of springs 53a-53c, the springs being so chosen that the displacement of the weight is a substantially linear function of the angle of inclination of the vehicle. The weight carries two toothed racks 54d, 54g which mesh with respective gears 65d, 65g on rods 61d, 61g carrying pinions 64d, 64g in mesh with the toothed ring 16. When the vehicle is travelling straight ahead the weight is locked by a point 80 carried by a rod 81. When the handle bars are turned the vehicle fork, together with the headlamp and transducer, turns about the axis AA relative to the vehicle frame which carries a pair of arcuate cam tracks 101, 102. At the beginning of the turn a roller 83 carried by the rod 81 leaves a notch 102a in the cam track 102 and thereby withdraws the point 80 to release the weight. The rods 61d, 61g are extended by adjustable links 66d, 66g carrying rollers 67d, 67g engaged by the cam track 101, and as the fork turns one of the rollers moves towards the centre of the central part 101a of the track whilst the other engages one of the side parts 101b and thereby withdraws its respective pinion from engagement with the ring 16, leaving the other pinion to turn the ring as the weight moves downwardly in its casing. A small hole 55 in the bottom of the casing enables the transducer to serve as a dashpot. In an alternative embodiment, Fig. 8, movement of the weight 152 against the resistance of a drum spring (153a) turns a rotary potentiometer 158 which controls the operation of an electric motor 200 driving the optical system (10). A movable control segment 370 attached to the fork controls microswitches M2, M3. When the handlebar is turned, microswitch M2 is closed, and energizes winding 191 to retract stud 190 which locks the weight 152 in its upper position, and microswitch M3 is opened or closed, according to whether the turn is to the left or right, to control a change-over relay Ri. The potential of the slider of potentiometer 158 and the potential of the slider of a rotary reference potentiometer 258 driven by the motor 200 are applied in opposite directions to amplifiers A1, A2 the outputs of which are fed to the terminals of the motor, which is of the reversible D.C. type. The motor shaft rotates until the two potentiometers are in equilibrium.